SyslogAppenderBase truncates very long messages to 256k, which is not very useful limit, since SyslogOutputStream supports only UDP, which has maximum message size of 64k. Messages over 64k result in "java.io.IOException: Message too long" (from DatagramSocket.send, called from SyslogOutputStream.flush), but this exception is visible only in logger context status...

Proposed fix: truncate long messages instead of discarding them. More specifically, change MSG_SIZE_LIMIT in SyslogAppenderBase to 65000.